When a graphics card is detached from or installed to a casing, a user needs to use both hands to press or pull three different places on the graphics card. However, it is difficult to guarantee the balance of the force applied on each place. During the installation or removal of the graphics card, if the forces applied by the user are unbalanced, it is difficult to keep the graphics card in a horizontal manner, leading to the difficulty in installation or removal of the graphics card. More seriously, it may cause connectors of the graphics card and the main circuit board to connect in an undesired manner and result in the damage thereof.
Accordingly, an improved detachable assembly device to solve the above issues is desirable.